There is already known a disk brake pad of the type defined above, illustrated in FIG. 1 which generally shows a brake disk 1 which is overlapped by a cover 2 which is composed of two arms 20 which are connected by means of two bridge-like members 21. These two arms 20 in the form of a “U” extend from one side and the other of the disk 1 and each carry a brake pad. The brake pads 3 are provided at the ends thereof with lugs 31 for assembly thereof in the housings 22 of each arm, via a guiding spring 4 with which each housing 22 is provided and which cooperates with the lug 31 of the pad which is itself provided with an auxiliary spring 5 in accordance with the prior art.
The lugs 31 at the two ends of the pad 3 slide axially in the guiding members 4 and are held by the spring 5, that is to say, perpendicularly relative to the plane of FIG. 1.
The function of the guiding members 4 is to guide the pad for the braking and its return into the position not in contact with the brake disk 1 and to damp the impact of the lugs 31 against the base of each housing 22 when the pads 3 are driven by the disk 1 during a braking phase.
According to FIGS. 2A, 2B, 2C, the known brake pad 3 comprises in the lugs 31 thereof two grooves 10, each for receiving a spring 5 known as a “helical spring” owing to its shape wound into a helix terminating in a fixing tongue 51. This spring 5 is engaged with the tongue 51 thereof in the groove 10 and the pad 3 equipped in this manner is then slid into the housings 22 (FIG. 1).
FIG. 2B is an enlarged view of a lug 31 which shows the groove 10. FIG. 2C is a sectioned view along II-II of FIG. 2B showing the cross-section of the groove 10. FIG. 3 is an enlarged sectioned view along III-III of FIG. 2 showing more specifically the shape of the groove 10 which has a generally rectangular cross-section with a base 11 and two sides 12, 13 which are connected to the base by means of fillets 14, 15. The inlet of the groove 10 in the face 32 of the lug is also bordered by fillets 16, 17.
The tongue 51 of the helical spring 5 is illustrated in cross-section in a state installed in the groove 10.
This tongue 51 abuts via the corners 51a, 51b thereof against the fillets 14, 15 of the groove so that the positioning of this tongue 51 and consequently that of the spring 5 and the pad 3 are not stable. The tongue 51 can tilt and be placed in the position illustrated with broken lines.
The tongue 51 can abut against the base 11 of the groove 10 only if the width thereof is sufficiently reduced so that the corners 51a, 51b thereof do not extend as far as the fillets 14 and/or 15. In this case, however, the tongue 51 floats in the groove 10 and can slide transversely and nonetheless risks moving into abutment via a corner 51a or 51b against the fillet 14, 15 or against the side 12, 13 of the groove.
Generally, the retention of the spring 5 on the lug 31 is not stable and creates a floating action in respect of the retention of the brake pad 3 in the housings 22 (FIG. 1).
An object of the present disclosure is to develop a disk brake plate which allows the rotation of the radial spring to be reduced after mounting the groove and allows an error in assembling an inappropriate radial spring to be prevented.